ABSTRACT
Public health considerations in water supply have largely addressed the issue of minimizing the occurrence of coliform bacteria and thereby the probability that intestinal pathogens may be present. Most of these organisms in drinking water are ubiquitous and may include some potentially pathogenic strains as well as a large number of saprophytic organisms. All of these microorganisms utilize a variety of organic compounds in their metabolism and are thereby often referred to as heterotrophs. Coliform bacteria may occasionally be found among the variety of gram-negative bacteria present in drinking water. Heterotrophic bacteria in water supplies that are resistant to one or more antibiotics may pose a health threat if these strains are opportunistic pathogens or serve as donors of the resistant factor to other bacteria that could be pathogens. Antibiotic resistant (R factor) bacteria may originate in surface-water sources used for public water supplies.
